Ballistic Impact Dynamic Modeling of Fabric for New Protection Systems

Accomplishing various missions that the US armed forces are called upon to perform often puts their personnel and equipment in harm's way. A common threat is exposure to a variety of ballistic projectiles that range from high-velocity armor-penetrating projectiles to knife stabbing of soldiers. Fabrics are used in a variety of ballistic shields that range from personnel vests to vehicle protective systems. This project will develop practical software for the analysis and optimal design of fabric systems to protect against ballistic threats. The key impediment to this development is the availability of a model that allows accurate representation of the projectile-fabric impact/penetration at a reasonable computational effort. This research will overcome this difficulty through the development and use of a multi-scale constitutive law where the fabric layers will be modeled as a membrane or shell at the macro level, and the yarn-to-yarn interaction will be modeled at the micro-level. The micro-level will be addressed locally at the integration (Gauss) points within each finite element. Globally, the impact will be modeled using explicit finite element simulations. The micro-level will incorporate viscous effects to enable the modeling of fabric impregnated with shear thickening fluids.